XBP1 and Parkinson disease: This neuroprotective effect was accompanied by the up-regulation of several UPR effectors in the SNpc of animals in the absence of pro-apoptotic markers such as Chop. This phenotype correlated with the presence of poly-ubiquitinated proteins and large inclusion bodies in dopaminergic neurons of XBP1 deficient animals, resembling the classical alterations observed in PD.